In recent years, increasingly sophisticated telematics systems have been developed to detect vehicle locations as well as the speed and direction at which the vehicle is traveling. Systems have been developed for monitoring fixed customer locations as well as for vehicle applications. Upon detecting a crash condition, the on-board system activates a cellular transceiver to initiate a cellular telephone call to a call center of the telematics service provider (TSP). Upon connection to the call center, the system may communicate certain data, such as location determined by global positioning satellite (GPS) processing, identification data and crash related data. After the data transmission, the call is converted to a voice call in which a TSP representative at the call center can attempt voice communication with an occupant of the vehicle. The TSP also offers mechanisms for the representative to contact emergency service personnel in the area, to respond appropriately to the incident. More recently, such systems have been enhanced to offer other related services, such as navigation services like turn-by-turn directions. GPS based on-board navigation systems have also become common, which provide the vehicle operator with location and velocity information. However, these telematics and navigation systems generally do not provide information that may help avoid collisions.
Additionally, on-board systems have been developed that may monitor one or more sensors to alert the driver of the nearness of certain unseen obstacles, for example, while parking or backing up. Such an on-board system monitors the location and velocity of its vehicle and alerts the driver of unseen obstacles, such as other vehicles, for example, when the other vehicles come within a few feet of the sensors. As another example, adaptive cruise control systems provide an adaptive vehicle speed control, based on sensing of another vehicle or target in front of the host vehicle. Although these sensing technologies provide some proximity information based on direct sensing of another vehicle or object, the on-board system receives no information about the locations or velocities of other vehicles in the area. The sensors may not alert the user of the nearness of other vehicles until it is too late to avoid these obstacles when traveling at significant speeds. This often results in vehicles unexpectedly coming into close proximity at speeds which may make it impossible to maneuver to avoid each other, thereby allowing collisions to occur.